Use of a composition in order to improve the spray from the injectors of a combustion engine

ABSTRACT

The present invention provides the use of a composition for improving the atomization of injectors of an internal combustion engine, the composition including, by weight, relative to the total weight of the composition, 60% to 95% of a mixture of at least first and second fatty diamines, the diamines being different, and 5% to 40% of a solvent.

The present invention relates to the use of a composition for improving the atomization of injectors, whether brand-new or clogged, for an internal combustion engine that equips, in particular, a land vehicle, an aircraft, or a sea or river transport vehicle, or even an electricity generator set.

In general, a combustion mixture is formed by putting fuel (gasoline, diesel) into contact with oxidizer (generally air taken from the atmosphere) in forms that encourage the initiation and the propagation of combustion, and the exhausting of reaction products. The ideal situation is thus to mix the fuel and the oxidizer homogeneously in gaseous form, with large- and small-scale stirring movements in stoichiometric conditions. Unfortunately, the fuel is usually in liquid form. A fundamental function of internal combustion engines thus consists in transforming the liquid fuel into vapor. This step is performed by an injector device.

In order to guarantee correct combustion, the injector device needs to admit, into the combustion chamber of an engine, a quantity of fuel that needs to be directed in the direction that promotes the best combustion, and it needs to do this, at a certain pressure so as to obtain good penetration (namely so as to obtain an air and fuel mixture that is homogeneous and that can reach the locations of the chamber the furthest from the injectors), and also so as to obtain good atomization (passing from the liquid state to the fine-droplet state), and a good insertion rate (quantity injected per unit of time or per unit crankshaft angle), while guaranteeing sealing relative to the combustion chamber. To do this, the injector device comprises an injector-holder and an injector. The injector-holder makes it possible to channel the admission and the return of fuel and to support a setting spring. In addition, it possesses a system of adjusting said setting spring. Fuel may be admitted into the injector by means of a solenoid valve, which is opened and closed under the control of a computer that manages all of the functions of the engine. The injector comprises two parts: a needle and a nozzle, the nozzle presenting a calibrated orifice that makes it possible to atomize the fuel in the form of micro-droplets. The orifice may have various configurations. Specifically, there exist hole, pintle, swirl, air-assisted, jet-impact, vibration, or vapor injectors.

For example, hole injector nozzles generally present 2 to 12 holes of diameter that is small, about 0.2 millimeters (mm) to 0.4 mm. This type of injector is used in particular on direct injection engines with calibration pressure that is high (200 bars to 400 bars). Orifices of diameters that are less than 0.1 mm currently exist on injectors connected to a common rail and having pressure that is about 2000 bars.

It is also desirable to treat the fuel so as to optimize atomization regardless of the type of injectors used.

Furthermore, the use of degraded fuels (phase changes, presence of sludge, high concentration of water), and the wear of injectors result in combustion difficulties (poor atomization of the injectors). This applies in particular for hole injectors. It has been calculated that a deposit of a few micrometers of soot, about 5 micrometers (μm), on an injector reduces its flowrate by about 25%. Unfortunately, on a diesel engined vehicle, such a deposit of soot on an injector may result in the turbo clogging, the catalyst and the particle filter clogging, the exhaust gas recirculation (EGR) valve clogging with excessive recycling and lack of air, and the manifold and the admission valves clogging, resulting in the engine being starved of oxygen.

Consequently, in the prior-art, there exists a need to provide a composition that makes it possible to avoid the injector device clogging.

In the prior-art, document EP 2 305 780 is known, which describes an emulsifying composition for homogenizing and re-emulsifying a mineral-oil, vegetable-oil, and water based fuel. In particular, that composition comprises, by weight, relative to its total weight: 5% to 40% of N-oleyl-1,3-propylene diamine, 50% to 95% of N,N′,N′-polyoxyethylene N-tallow propylene diamine; and 5% to 40% of a solvent. It is stated in that document that the composition makes it possible to re-emulsify the various components of the fuel (mineral-oil, water, vegetable-oil . . . ) and thus to improve peptization and rheology (the viscosity of the fuel will then be constant), also resulting in an improvement in combustion (homogeneous combustion).

That document thus does not refer to a composition that is suitable for avoiding clogging of an injector device of an internal combustion engine.

An object of the present invention is to propose a novel composition that avoids the above-mentioned drawbacks, at least in part.

The present invention provides the use of a composition for improving the atomization of injectors of an internal combustion engine, said composition comprising, by weight, relative to the total weight of said composition, 60% to 95% of a mixture of at least first and second fatty diamines, said diamines being different, and 5% to 40% of a solvent.

The Applicant company has discovered that the use of a composition as described above makes it possible not only to re-establish the atomization of new or clogged injectors, but also to eliminate any deposits in the combustion chambers of a machine (such as an electricity generator set) or of an internal combustion vehicle such as a land vehicle, an aircraft, or a sea or river transport vehicle.

For example, when the composition is used to clean the engine of a motor vehicle, said composition makes it possible not only to clean the catalysts, but also to facilitate the regeneration of particle filters, to descale the turbos, and thus to increase the efficiency of the engine, and to do this without it being necessary to strip it down.

Without wanting to be bound by any theory, the Applicant suggests that the various advantages of the present composition appear to result from the chemical structure of the various compounds of the composition.

Furthermore, on reading document EP 2 305 780, it can be seen that the composition described in that document presents an effect on the rheology of the fuel and improves its surface state. However, the person skilled in the art could not imagine from that teaching that the composition would also have an effect on the atomization of injectors. For that to be true, it would have been necessary for the composition described in that document to have an effect of reducing the diameter of the droplets of the fuel and/or an effect on their fractionation. Those effects are neither described nor suggested by document EP 2 305 780.

It thus appears, in unexpected and entirely surprising manner, that the composition makes it possible to improve the atomization of injectors of an internal combustion engine.

In order to obtain the above-mentioned effects, the composition of the invention may be poured directly into the tank of the combustion vehicle or machine, so as to obtain a concentration of fatty amines lying in the range 0.5 milligrams per liter (mg/L) to 20 mg/L, preferably in the range 0.8 mg/L to 15 mg/L, and still more preferably in the range 3 mg/L to 12 mg/L. This concentration is suitable for improving the atomization of injectors of the combustion vehicle or machine. After consuming this quantity of fuel, the tank may be filled once more with the composition.

The present invention may also provide a method of improving the atomization of injectors of an internal combustion engine, which method comprises mixing a fuel or a liquid oxidizer with a composition, as described in the present application. The composition generally comprises, by weight, relative to the total weight of said composition, 60% to 95% of a mixture of at least first and second fatty diamines, said diamines being different, and 5% to 40% of a solvent. The method of the invention also includes all of the characteristics described in the present application for the composition used to improve the atomization of injectors.

In the present invention, unless specified to the contrary, the indication of a range of values “X to Y” or “in the range X and Y” should be understood as including the values X and Y.

Preferably, said first and second diamines suitable for the present invention are selected from a diamine that includes at least one saturated or unsaturated fatty acid radical having 4 to 20, preferably 8 to 18, carbon atoms, such as a decyl, stearyl, oleyl, ricinoleyl, linoleyl, lauryl, myristyl, capryl, and palmityl radical, or a mixture of C₄-C₂₀, preferably C₈-C₁₈, alkyl chains, such as copra, tallow, or coconut chains (an alkyl radical derived from copra, tallow, or coconut fatty acid).

Preferably, the first diamine satisfies formula I below:

where:

-   -   m is an integer in the range 1 to 8; and     -   R²⁶, R²⁷, R²⁸, and R²⁹ are independently of one another:         hydrogen, a C₁-C₄ linear or branched alkyl radical, or a C₄-C₃₀,         preferably C₈-C₂₀, linear or branched alkyl radical, on         condition that at least one from among R²⁶, R²⁷, R²⁸, and R²⁹ is         a C₄-C₃₀, preferably C₈-C₂₀, linear or branched alkyl radical.

Advantageously, only one group from among R²⁶, R²⁷, R²⁸, and R²⁹ carries the C₄-C₃₀ linear or branched alkyl radical, preferably C₈-C₂₀ linear.

In particular, three groups from among R²⁶, R²⁷, R²⁸, and R²⁹ are hydrogen.

According to a characteristic of the invention, the C₄-C₃₀ linear or branched alkyl radical is selected from: a decyl, stearyl, oleyl, ricinoleyl, linoleyl, lauryl, myristyl, capryl, and palmityl radical, or an alkyl radical derived from copra, tallow, or coconut fatty acid (mixture of C₄-C₂₀, preferably C₈-C₁₈, alkyl chains).

In preferred manner, the first diamine is selected from: N-octyl-1,3 propylene diamine; N-decyl-1,3 propylene diamine; N-dodecyl-1,3 propylene diamine; N-tetradecyl-1,3 propylene diamine; N-octodecyl-1,3 propylene diamine; N-oleyl-1,3 propylene diamine; and N-alkyl 1,3 propylene diamine having an alkyl radical that is derived from a copra, tallow, or coconut fatty acid; and a mixture thereof.

In particular, the N-oleyl-1,3-propylene diamine is preferred (m=3, R²⁶, R²⁷, R²⁸=H and R²⁹=an aleyl radical).

The N-oleyl-1,3 propylene diamine compound corresponds to CAS N^(o) 7173-62-8. In particular, the products sold under the trade name DINORAM® O by the supplier CECA and Duomeen® O by the supplier Akzo-Nobel may be suitable for the present invention.

The first diamine is present in the composition at a content, by weight, relative to the total weight of the composition, of 5% to 35%, preferably 8% to 22%, and still more preferably 12% to 17%.

Advantageously, the second diamine is a polyethoxylated alkyl diamine.

A polyethoxylated alkyl diamine suitable for the present invention is preferably a compound of formula II below:

where:

-   -   the sum of x, y, and z is 2 to 25; and     -   R is a C₃-C₂₂ alkyl radical.

Preferably, the alkyl radical presents a molecular weight in the range 220 grams per mole (g/mol) to 515 g/mol.

Advantageously, the polyethoxylated alkyl diamine is at least one compound selected from: N,N′,N′-tris(2-hydroxyethyl)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (25)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (20)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (15)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (10)-N-tallow-1,3 propylene diamine; and N,N′,N′-polyoxyethylene (7)-N-tallow-1,3 propylene diamine; and a mixture thereof.

Still more advantageously, the polyethoxylated alkyl diamine is at least one compound selected from: N,N′,N′-polyoxyethylene (25)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (12)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (10)-N-tallow-1,3 propylene diamine; N,N′,N′-polyoxyethylene (7)-N-tallow-1,3 propylene diamine; and N,N′,N′-polyoxyethylene (3)-N-tallow-1,3 propylene diamine; and a mixture thereof.

In particular, the compound having 7 moles of ethylene oxide (N,N′,N′-polyoxyethylene (7)-N-tallow-1,3 propylene diamine) is preferred. It is liquid in ambient air (25° C.) and comprises approximately 3% of C₁₄, 30% of C₁₆, 40% of C₁₅, 26% of C₁₈, and 1% of C₂₀. It is known as a wetting, dispersing, and emulsifying agent. The product DINORAMOX® S7 from the supplier CECA ARKEMA GROUP is suitable in particular for the present composition.

The second diamine is present in the composition at a content, by weight, relative to the total weight of the composition, of 40% to 90%, preferably 55% to 85%, and still more preferably 60% to 78%.

The solvent suitable for the present invention is selected from: isopropylbenzene; gasoline; heating oil; and kerosine; and a mixture thereof; preferably the solvent is selected from isopropylbenzene and/or gasoline. Preferably, the solvent suitable for the present invention is isopropylbenzene (CAS N^(o) 98-82-8).

The solvent is present in the composition at a content, by weight, relative to the total weight of the composition, of 5% to 40%, in particular 5% to 30%, preferably 7% to 25%, and still more preferably 12% to 19%.

Preferably, the composition comprises, by weight, relative to the total weight of said composition:

a) 5% to 35%, preferably 8% to 22% of N-oleyl-1,3-propylene diamine;

b) 40% to 90%, preferably 55% to 85% of N,N′,N′-polyoxyethylene N-tallow propylene diamine; and

c) 5% to 30%, preferably 7% to 25% of a solvent.

Specifically, the present Applicant has found that these two selections, i.e. firstly the selection of amines to use from among all existing amines, and secondly the selection of clearly specific concentrations, make it possible to obtain a composition that serves to improve the atomization of injectors and the cleaning of said injectors of an engine, and in particular of a diesel engine.

The composition of the invention may be prepared in accordance with the method described below.

The method comprises the following steps:

i) heating the first diamine and the second diamine so as to obtain a first liquid mixture; and

ii) adding the solvent to the first mixture while stirring, so as to obtain a liquid composition.

Preferably, the heating step i) is performed at a temperature in the range 30° C. to 50° C., preferably in the range 35° C. to 45° C., and still more preferably at 40° C.

Preferably, stirring occurs in the range 20 revolutions per minute (rpm) to 50 rpm during heating i).

According to a characteristic of the invention, heating and stirring are performed for at least 5 days.

Advantageously, the solvent is isopropylbenzene, such that the composition resulting from step ii) is still liquid at temperatures situated in the range 0° C. to 20° C.

Purely illustrative and non-limiting examples of compositions within the ambit of the invention are described below. These tests were performed in order to demonstrate the stability of the fuel of the present invention over time, and its effectiveness.

EXAMPLE 1 Make Up of the Composition of the Invention

For the following tests, the composition comprised, by weight, relative to the total weight of the composition:

a) 14.76% of N-oleyl-1,3-propylene diamine (DINORAM® O);

b) 69.53% of N,N′,N′-polyoxyethylene N-tallow propylene diamine (DINORAMOX® S7); and

c) 15.71% of isopropylbenzene.

In the description below, this composition is referred to as COMP 1.

EXAMPLE 2 Combustion Analysis on an Airplane Tow Tractor

A first test was performed on a type TPX 806 diesel airplane tow tractor presenting the following characteristics:

-   -   Cummins engines: ref.: 6CTA8.3     -   Bosch injectors ref. Cummins: 3802095     -   Bosch fuel pump     -   Tank capacity: 325 liters     -   Hourly consumption: 30 liters/hour

The flowrates of various rejected gases were measured before and after treatment, namely after adding 2 liters of COMP 1 to the full tank of the tow tractor.

The following results were obtained:

Kilometrage/load Idling Half-load Full-load CO₂ (%) 5193 h 2.71 3.25 3.94 5648 h 1.72 2.24 2.97 Variation (%) −36.5 −31.1 −24.6 O₂ (%) 5193 h 17.02 16.33 15.44 5648 h 18.48 17.84 17.01 Variation (%) +8.58 +9.25 +10.01 NO_(x)* (ppm) 5193 h 902.00 727.00 626.00 5648 h 305.00 166.00 170.00 Variation (%) −66.19 −77.17 −77.84 HC** (in ppm) 5193 h 5.00 6.00 6.00 5648 h 6.00 6.00 6.00 Variation (%) +20.00 0.00 0.00 CO (%) 5193 h 0.014 0.029 0.019 5648 h 0.008 0.014 0.014 Variation (%) −42.86 −41.72 −26.32 *NO_(x): nitrogen oxide **HC: unburnt hydrocarbons

In the invention, nitrogen oxides NO_(x) are emissions covering: nitrogen monoxide NO; nitrogen dioxide NO₂; nitrogen protoxide N₂O; nitrogen pentaoxide N₂O₅; nitrogen tetraoxide N₂O₄; and nitrogen trioxide N₂O₃; and a mixture thereof.

After treatment and 275 hours of use, the test after treatment with the COMP 1 of the invention showed substantial drops in the CO₂ and NO_(x) values. The NO_(x) value was three and a half times smaller than the value of the first measurement made before treatment. Furthermore, the engine of the airplane tow tractor presented better combustion as a result of more effective atomization of the injectors (a drop in CO₂ and an increase in rejected O₂). Continued treatment enabled the engine to be unclogged completely.

EXAMPLE 3 Combustion Analysis of an Engine of an Electricity Generator Set

A second test was performed on a type GPU 849 diesel electricity generator set having the following characteristics:

-   -   John Deere engine (ref.: 6068TF250)     -   John Deere injectors (ref.: RE48786)     -   Stanadyne injection pump (ref.: RE69792)     -   Tank capacity: 265 liters     -   Hourly consumption: 18.5 liters/hour

The flowrates of various rejected gases were measured before and after treatment, namely after adding 2 liters of COMP 1 to the full tank of the electricity generator set.

The following results were obtained:

Kilometrage/load Idling Half-load Full-load CO₂ (%) 8294 h 2.32 6.17 6.66 8894 h 1.04 3.61 4.54 Variation (%) −55.2 −41.5 −31.8 O₂ (%) 8294 h 17.72 12.33 11.70 8894 h 19.29 15.83 14.62 Variation (%) +8.86 +28.39 +24.96 NO_(x)* (ppm) 8294 h 166.00 557.00 806.00 8894 h 172.00 240.00 559.00 Variation (%) +3.61 −56.91 −30.65 HC (unburnt hydrocarbons in ppm) 8294 h 3.00 2.00 3.00 8894 h 4.00 2.00 3.00 CO (%) 8294 h 0.02 0.008 0.005 8894 h 0.010 0.012 0.006 *NO_(x): nitrogen oxide **HC: unburnt hydrocarbons

Before treatment, the engine of the electricity generator set presented very poor combustion, specifically the CO₂ and NO_(x) values were very high at half-load and full-load. After treatment (plus 600 hours of operation) with COMP 1, the atomization of injectors of the electricity generator set was improved.

In conclusion, examples 2 and 3 above show that the composition of the present invention makes it possible to improve the atomization of injectors.

Although the invention is described above in relation to a particular embodiment, naturally it is not limited by said embodiment, and it includes any equivalent techniques of the means described and any combinations thereof if said combinations are within the ambit of the invention. 

1. Method of improving the atomization of a fuel or a liquid oxidizer of injectors of an internal combustion engine, which method comprising mixing said fuel or said liquid oxidizer with a composition comprising, by weight, relative to the total weight of said composition, 60% to 95% of a mixture of at least first and second fatty diamines, said diamines being different, and 5% to 40% of a solvent.
 2. Method according to claim 1, wherein said first and second diamines are selected from a diamine that includes at least one saturated or unsaturated fatty acid radical having 4 to 20 carbon atoms, or an alkyl radical derived from copra, tallow, or coconut oleic fatty acid.
 3. Method according to claim 1, wherein the first diamine satisfies formula I below:

where: m is an integer in the range 1 to 8; and R²⁶, R²⁷, R²⁸, and R²⁹ are independently of one another: hydrogen, a C₁-C₄ linear or branched alkyl radical, or a C₄-C₃₀, preferably C₈-C₂₀, linear or branched alkyl radical, on condition that at least one from among R²⁶, R²⁷, R²⁸, and R²⁹ is a C₄-C₃₀, preferably C₈-C₂₀, linear or branched alkyl radical.
 4. Method according to claim 3, wherein said C₄-C₃₀ linear or branched alkyl radical is selected from: a decyl; stearyl, oleyl, ricinoleyl, linoleyl, lauryl, myristyl, capryl, and palmityl radical, or an alkyl radical derived from copra, tallow, or coconut fatty acid.
 5. Method according to claim 3, wherein the first diamine is an N-oleyl-1,3 propylene diamine.
 6. Method according to claim 1, wherein the second diamine is a polyethoxylated alkyl diamine.
 7. Method according to claim 6, wherein the polyethoxylated alkyl diamine is a compound of formula II below:

where: the sum of x, y, and z is 2 to 25; and R is a C₃-C₂₂ alkyl radical.
 8. Method according to claim 7, wherein the polyethoxylated alkyl diamine is at least one compound selected from: N,N′,N′-tris(2-hydroxyethyl)-N-tallow-1,3 propylene diamine; and N,N′,N′-polyoxyethylene-N-tallow-1,3 propylene diamine; and preferably the polyethoxylated alkyl diamine is N,N′,N′-polyoxyethylene-N-tallow-1,3 propylene diamine.
 9. Method according to claim 1, wherein the composition comprises, by weight, relative to the total weight of the emulsion: a) at least 5% to 35% of N-oleyl-1,3-propylene diamine; b) at least 40% to 90% of N,N′,N′-polyoxyethylene N-tallow propylene diamine; and c) at least 5% to 40% of a solvent.
 10. Method according to claim 1, wherein the solvent is selected from: isopropylbenzene; gasoline; heating oil; and kerosine; and a mixture thereof.
 11. Method according to claim 1, so as to obtain a concentration of fatty amines in the treated fuel lying in the range from 0.5 mg/L to 20 mg/L.
 12. Method according to claim 11, wherein the concentration of fatty amines in the treated fuel lying in the range from 0.8 mg/L to 15 mg/L.
 13. Method according to claim 12, wherein the concentration of fatty amines in the treated fuel lying in the range from 3 mg/L to 12 mg/L.
 14. Method according to claim 2, wherein the first diamine satisfies formula I below:

where: m is an integer in the range 1 to 8; and R²⁶, R²⁷, R²⁸, and R²⁹ are independently of one another: hydrogen, a C₁-C₄ linear or branched alkyl radical, or a C₄-C₃₀, preferably C₈-C₂₀, linear or branched alkyl radical, on condition that at least one from among R²⁶, R²⁷, R²⁸, and R²⁹ is a C₄-C₃₀, preferably C₈-C₂₀, linear or branched alkyl radical. 